This nation's capital was built by Siegfried I, and it was returned to Haps
This nation's capital was built by Siegfried I, and it was returned to Hapsburg rule by the Treaty of Ryswick after the Nine Years' War. A crisis over this nation in 1867 almost led to war, and this country was ruled by the House of Orange until 1890. Known as the Gibraltar of the North, this nation's fortifications were improved upon by Vauban under Louis XIV. It is ruled by Grand Dukes of the House of Nassau and draws most of its wealth from banking. For 10 points, name this member of the Benelux, a small nation south of Belgium.
This nation's capital was built by Siegfried I, and it was returned to Hapsburg rule by the Treaty of Ryswick after the Nine Years' War.
Grand Duchy of {Luxembourg}